This invention relates to packet networks and more specifically relates to controlling how packets are processed within a portion of a network of non-homogeneous nodes.
Communication networks, especially Internet protocol (IP) networks, are widely used. Packets transmitted over these networks may carry a variety of information. Some information can be categorized as data, wherein packets carrying data do not normally require special handling measures, e.g. quality of service. However, packets carrying other types of information, e.g. voice over Internet protocol (VOIP), will benefit from a higher quality of service such as ensuring adequate bandwidth exists and that arrival time delays are maintained within predetermined limits.
In existing practice, a reservation signaling protocol can be utilized to establish a higher quality of service in a packet network between a communication originator and a communication recipient. This requires that the communication originator initiate a signaling message addressed to the communication recipient. The packet nodes along the communication path receive and interpret this message, and the communication recipient must receive this message before it transmits a reservation request signaling message. The packet nodes along the communication path then set up a specified quality of service communication path from the communication originator to the communication recipient. It will be apparent that at least the communication originator, communication recipient, and one or more nodes in the interior of the network must be able to recognize the signaling message in order to implement this reservation signaling protocol. That is, the network must be substantially homogeneous with regard to capability of the nodes of the network to recognize control instructions and implement the requested functions.
It is desirable that new communication protocols be able to be incrementally deployed within a subset of nodes of a packet network. That is, even within a network owned by the same entity it may not be desirable or even feasible to upgrade all nodes with a new communication protocol at the same time. Even if one entire network is upgraded, communications often traverse multiple networks owned by different entities. Therefore, it is unlikely that all of the different owners of the various networks would implement a new communication protocol at all of the nodes in each of the networks at the same time. Thus, it cannot be assumed that a communication path will only traverse nodes that are substantially homogeneous with regard to communication protocols. In particular, it is desirable for a communication recipient to be able to deploy a new communication protocol without requiring the communication originator to deploy the same communication protocol and vice-versa.
As will be discussed in the Detailed Description section, one aspect of the present invention resides in a recognition of the difficulties presented by the incremental deployment of a new communication protocol in a packet network. Such a deployment is further complicated in view of the asymmetric routes normally assigned for two-way communications between a communication originator and the communication recipient. Thus, there exists a need to support quality of service functions in a non-homogeneous packet network for at least such nodes that are capable of such support.